The bot, which was shown off at the IEEE/RSJ International Conference on Intelligent Robots and Systems this week, has a silicone skin, and moves by selectively inflating and deflating parts of its spherical body. But the locomotion system entails more than simple puffing and rolling: The video [see below] explains the “particle jamming” system of locomotion, “a mechanism by which material can transition from a liquid-like to a solid-like state.”

(According to IEEE, the video below is a little dated, but it’s still a good primer on “jamming.” The cool stuff starts at around 1:50.)